The present invention relates to a rocking mechanism employed in a printing device for rocking a ribbon cassette mounting a print ribbon in a vertical direction so that a desired printing zone is located to a printing position where the printing zone is opposed to a printing sheet on which a printing operation is executed.
Conventionally, in a printing device with such type rocking mechanism, the printing device is so arranged to be capable of detachably and attatchably providing a multiple zones ribbon cassette which houses a multiple zones ribbon where multiple printing zones with different colors are disposed in a width direction. The rocking mechanism is operated according to multiple color printing data outputted from a host machine. Thereby, one of the multiple zones is selected and the multiple zones ribbon cassette is rocked in a vertical direction, i.e., in a width direction so that the selected zone is opposed to a printing mechanism section for executing a printing operation with a color according to the selected zone.
In the printing device of this type, when single color printing data is outputted from the host machine, the multiple zones ribbon cassette is fixed in a vertical direction since a predetermined printing zone is opposed to the printing mechanism section according to the single color printing data and a single color printing operation is executed. Therefore, other printing zones are not used and are wasted. To prevent that, a single zone ribbon cassette housing a single zone ribbon which is provided with one printing zone in a width direction is used instead of the multiple zones ribbon cassette. The printing device prints data with a single color without a rocking operation.
However, when multiple color printing data is mistakenly outputted from the host machine while the single zone ribbon cassette is attached, since the printing device operates the rocking mechanism in accordance with the multiple color printing data having been inputted and the single printing zone is not opposed to the printing mechanism section, part of the printing operation is not executed on a printing sheet and the characters and/or symbols corresponding to the above mistaken printing operation are not printed on the printing sheet.